Sugarcane bagasse is a typical waste generated in the production of sugarcane and ethanol. This agro-industrial waste is commonly used as fuel in the industry boiler for the steam and energy generation. However, part of the bagasse waste is disposed and may pollute the environment. The fibers extracted from the sugarcane bagasse have been considered as addition to polymeric composites. In the present work epoxy composites incorporated with 30% in volume of continuous sugarcane bagasse fibers were evaluated in terms of their mechanical properties. As compared to the neat epoxy, the bagasse fiber displayed an increase in elastic modulus but a decrease in strength and ductility. The analysis of the composite microstructure by scanning electron microscopy revealed flaws and pores that could justify these preliminary obtained results.

Lignocellulosic fibers with relatively unknowns mechanical properties such as those extracted from the sponge gourd, are being investigated as polymer composites reinforcement. The use of natural fibers are related to environmental , technical, economical and social advantages. An important possibility of improving the mechanical properties is the fact that lignocellulosic fibers may present tensile strength inversely correlated with their diameter. Therefore, this possibility was investigated in the present work regarding sponge gourd fibers by means of the Weibull statistic analysis. The results supported a hyperbolic inverse correlation between the strength of sponge gourd fibers with their diameter. Scanning electron microscopy observation of fibers with different diameters revealed possible mechanisms for the strength inverse correlation with diameter.

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Fibers obtained from de sugarcane bagasse are being investigated as possible engineering materials. Their application as reinforcement of polymer composites is of interest due not only to environmental benefits associated with a waste recycling but also to their biodegradable and renewable characterisitics. Since it is known that many lignocellulosic fibers present a tensile strength inverse dependence with the diameter, this possibility was investigated on bagasse fibers. By means of the Weibull analysis, it was found that the thinner the bagasse fiber, the greater the strength. Fracture observation of bagasse fibers by scanning electron microscopy, indicated possible mechanisms related to this inverse correlation.

O presente artigo tem por objetivo investigar os efeitos de três variáveis do sistema reacional do processo de fosfatização com manganês por imersão a quente empregado nos armamentos leves do Exército Brasileiro. A avaliação da influência destas variáveis foi feita através da realização de experimentos baseados em um planejamento fatorial com dois níveis para as três variáveis, sendo elas o tempo, a concentração do reagente fosfatizante e a concentração de íons ferroso no meio reacional. Os resultados mostraram que as variáveis selecionadas possuem efeitos de interação significativos, de forma que devem ser avaliadas em conjunto. Concluiu-se que: (1) o tempo é importante, em especial, para o ganho de massa do revestimento e para o refinamento dos cristais; (2) a concentração de reagente fosfatizante, por sua vez, mostrou-se extremamente impactante na cristalização bem definida dos revestimentos, na contribuição de manganês nos cristais e na obtenção de camadas com elevado peso; (3) a concentração de íons ferrosos contribuiu para o aparecimento de granulações mais grosseiras no revestimento fosfático.